Spatio-temporal variation in physio-chemical parameters over a 20-year period, potential future strategies for management: A case study of Dal Lake, NW Himalaya India

Analysis of physio chemical parameters (pH, TDS, DO, COD, Ca2+, Na+, Mg2+, K+, SO42-, HCO3- , Cl-, NO3-N and TP) were carried out at thirty-eight (38) sampling sites during pre and postmonsoon seasons from 2016 to 2019. Results show TP varied from (0.3- 1.6 mg/l with an average value of 0.9 mg/l), NO3-N varied from (0.2-1.5 mg/l with an average value of 0.7 mg/l) and COD varied from (11-98 mg/l with an average value of 47.80 mg/l) and were compared with previous results of 1997 and 2007 to determine the decadal changes and impact of anthropogenic activities. Comparative results showed that TP, NO3-N, and COD had increased 2.3, 2.0, 1.75 times, respectively from 1997 to 2017 while the concentration of DO has decreased from the last two decades. The present experimental analysis indicates that Dal Lake is exposed to anthro-urban intensification due to an increase in anthropogenic activities in the catchment area, affecting the overall hydrogeochemistry of lake water. Systemic insitu pliability can prevail till exsitu lacustrine management fortifies euoecism. Certain remedial measures are provided to manage the lake and to conserve its natural quality if implemented properly. (C) 2020 Elsevier B.V. All rights reserved.